Adapter



D. A. BENSON Feb. 18, 1964 ADAPTER Filed July 6, 1961 United States Patent Ofiice 3,121,388 latenteol Feb. 18, 1964 3,121,3323 ADAPTER Donald A. Benson, St. Panl, Minn, assignor to Minnesota Mining and Manufacturing Company, St. Pani, Minn, a corporation of Belaware Filed Italy 6, 1961, Ser. No. 122,239 Qlaims. (6i. lei-415.1)

This invention relates to lithographic printing presses and in particular to mechanisms for attaching imaged lithographic masters to the master cylinders of such presses.

For many years master cylinders of lithographic printing presses have been provided with two lines of hooks or pins mounted on adjustable supports just inside of the radial periphery of the longitudinally channeled cylinder, as a means of holding the appropriately terminally slotted or perforated flexible lithographic master onto the cylinder. The projections hold both the leading and trailing edges of the lithographic master firmly in position and provide the positive alignment required in multi-color printing.

Because perforating the lithographic masters adds to their cost, attempts have been made to employ masters having straight, imperforate edges, particularly for less exacting applications. Some recent presses are in fact equipped with master cylinders having master-clamping mechanisms with which such imperforate masters may be firmly retained; in addition, with these newer machines the straightedge master can be attached more rapidly and easily because when once the leading edge is firmly clamped, the tedious process of tensioning the trailing edge may be dispensed with. However, the clamp type cylinders represent a substantial investment, and substitution in the older style presses is difficult or in many cases impossible, so that many operators have been forced to continue the use of the more expensive and slower perforated or punched lithographic masters for all printing obs. 1 It is, therefore, an object of this invention to provide an inexpensive clamping means that can be simply and easily attached to a conventional hook bar or other fastener bar type master cylinder, thus rendering the press additionally receptive to straight-edge imperforate masters.

Another object is to provide for the conversion of older lithographic printing machines, designed to accept only apertured-edge lithographic masters, to a form in which they will equally well receive the straight-edge imperforate masters, at a minimum of expense and by means of a simple and inexpensive conversion element or adapter which may be easily and quickly attached to, and removed from, the leading fastener bar support of the original master cylinder.

A further object is to provide means for the attachment of master plates of any desired configuration, whether apertured or not and having either a scalloped edge or a straight edge, to the master cylinder with a minimum of effort and without reliance upon the cumbersome dual fastener-bar apparatus widely employed prior to the present invention.

These and other objects and advantages are attained by providing a simple, compact, positive acting clamp memher which fits into the very limited sub-radial space of the channeled surface area of the master cylinder. The clamp member is secured to the leading fastener-bar support at the flat area normally provided for supporting a handle member attachment. The clamp provides sufficient holding power to secure the master during the high speed lithographic process while yet permitting easy removal and replacement of such master by easy hand manipulation. The clamp comprises a highly tensioned,

outwardly positioned master-clamping member which urges the master plate against a cooperating anchoring surface on the clamp face. Although still greater holding or anchoring forces may be provided by using a knurled, grooved, ridged, or V-shaped anchoring surface, a flat surface is ordinarily adequate so long as the combination of clamping member and supporting face "will give the positioned lithographic master a sharp angle turn near its leading edge.

In the preferred method of attaching, the clamp is bolted to the leading fastener-bar support by bolts which fit into the two threaded holes present in the fastener-bar support and which normally are utilized only on the trailing fastener-bar support for the attachment of a handle member thereto. In another method, the attaching bolt replaces the set-screw normally provided for adjusting the position of the fastener-bar support.

in the drawing:

FlGURE 1 illustrates in central transverse section (section i-i of FIGURE 2) an adapter clamp in accordance with the present invention, the clamp being illustrated as mounted in position on a conventional hook-bar cylinder of a lithographic press, the fastener-bar support and the master cylinder wall being indicated in partial section and with broken lines;

FIGURE 2 is a partial top plan view of the adapter of FlGURE l partly broken away to show constructional details;

FEGURE 3 illustrates, in transverse section 33 of FIGURE 2, the adapter of FIGURES 1 and 2 at the position of the movable jaw hinge joint;

FEGURE 4 is a central transverse sectional elevation showing a modified form of the adapter;

FIGURE 5 is a partial rear elevation of the modified form shown in FEGURE 4 and illustrating the hinge joint; FZGURE 6 is a central transverse sectional elevation illustrating another modified form of the adapter;

FlGURES 7 and 8 are exploded end elevation and partial rear elevation respectively of a further and preferred modification of the adapter. FIGURE 9 is an auxiliary view showing the serrated-edge sheath component of the same preferred modification.

The adapter If; as illustrated in FIGURES 1-3 comprises a generally triangularly cross-sectioned elongate frame member having a perforated rearward extension 12 centrally and at the base of the triangular bar 11 for receiving the attaching bolt 1?. A hinge plate 14 affixed along the outward face of the triangular bar 11 supports hinge pin 29. A movable hinge plate 15 serving as a clamping member is rotatably secured to the elongate frame member by hinge pin 29. The inturned free edge In of said movable hinge plate 15 is directed toward the outward face of the bar 11 and into an elongate groove formed therein and defined by an inner surface 17 and a forward surface 13. Free edge 16 is pressed firmly against the surface 17 by torsion springs 13 pressing against the upright backside of the elongate frame member and the underside of the movable hinge plate 15. The movable hinge plate 15 has a depressing handle 27, centrally open as at 23 so as to allow access to attaching bolt 19. The adapter 1% lies wholly within the radial periphery 2d of the master cylinder 2i and is carried by the leading fastener-bar support 22, said support 22 being urged against the cylinder wall 23 by tension spring 24%. Hook bar assembly 25, as used with perforated masters, may remain attached to the end of the leading fastener bar member 22 by screws 26 or may be removed if preferred; or it may be formed integral with the bar. 7

Operation of the clamp is as follows. The inturned free edge of the movable hinge plate 15 is raised by depressing the handle 27. T .16 edge of a lithographic master is inserted and seated against the edge of the hinge plate 3 t 14, and the handle is released, thus permitting the inturne free edge 16 of the plate to force the edge portion of the master around the forward surface 18 of the groove and against the anchoring bottom surface 17.

FIGURES 2 and 3 show the movable hinge plate 15 of FIGURE 1 rotatably secured around the hinge pin 29 which in turn is supported by the fixed hinge plate 14. The latter is affixed to the bar 11 by welding or by means of suitable screws or pins as desired.

In the FIGURE 4 embodiment, the elongate frame member consists of the hinge pin 49 fitting through the channeled extended top edge portion 44 of the bar ill. The movable hinge plate 45 is rearwardly extended to form a depressing handle 47 having a bolt access opening 48.

As shown in detail in FIGURE 5, torsion spring 43 surrounds the hinge pin 49 which is supported by edge extension 44 of the bar 41 and in turn supports movable hinge plate 45 through tabs 42. The extended ends of the springs 43 bear against the upright rear face of the bar 41, and the inner face of the lever 47 to urge the inturned free edge of the plate 45 toward the grooved face of the bar.

In the FIGURE 6 embodiment, the affixed hinge plate 64- comprises the entire outer face of the elongate frame and is itself grooved. The inturned free edge as of movable hinge plate 65 is directed into the elongate groove, here defined by an inner surface 67 and a forward surface 68, under spring tension imparted by torsion springs 63. Flexed leaf springs or other equivalent tensioning members may replace the torsion springs.

FIGURE 7 illustrates additional alternative modifications in the outward face of the elongate frame. A thin metal sheath 72 fits closely around the backside and the outward face of bar 71. A serrated upturned edge provides a forward surface 78 which together with the anchoring surface 7'7 acts to give an inserted lithographic master a sharp angle turn when pressed against the surface 77 of the sheath 72 by the inturned free edge of the movable hinge plate 75. Raised tabs 81 provide a forward surface against which to abut the forward edge of an inserted master sheet. The hinge plate 74, which supports hinge pin 79, together with the sheath 72, is secured to the bar 71 by screws 70. The hinge plate 75 is extended along a central portion to provide a lever 76 which is centrally open to provide access to the perforated extension 80.

FIGURE 8 shows the movable hinge plate 75 rotatably secured around the hinge pin 7? which in turn is supported by the fixed hinge plate 74 The latter is afiixed to the bar 71 and in turn supports the sheath 72 therebetween by means of screws '70. One end of compressed spring 73 is afiixed to the under surface of hinge plate 75, while the other end presses against the outer surface of binge plate 74.

FIGURE 9 illustrates the integral upturned tabs 81 spaced longitudinally along sheath '72 that would provide an edge abutment for an inserted lithographic master.

My invention is thus seen to provide a clamp that can be easily attached within the limited sub-radial space of a lithographic master cylinder. This clamp provides for the conversion of lithographic printing machines, designed to accept only apertured-edge lithographic masters, to a form in which they will equally well receive imperforate masters, as well as masters havin perforate straight or scalloped leading edges.

What is claimed is as follows:

1. A clamp member suitable for attachment onto the leading fastener-bar support and fitting completely within the channeled space of a lithographic printing press master cylinder and adapted for use in the rapid attachment to and removal from said master cylinder of flexible lithographic printing plate masters, said clamp comprising:

(1) an elongate bar of generally right-triangular crosssectional shape having centrally disposed along the 2, right-angular axis a perforate mounting flange whose base is coplanar with the base surface of said triangular bar, an upright backside drilled and tapped to receive a plurality of retaining screws, and a forward outer face forming the hypotenuse;

(2) a flexible thin metal sheath conforming to the backside and the outer face of the elongate bar, said sheath being perforated for passage of said retaining screws, and being longitudinally upturned and serrated along the forward edge and also segmentally upturned parallel to and closely behind said serrated edge;

(3) a two-plate hinge having a fixed plate perforated for passage of said retaining screws when mounted along said backside and over the back segment of said sheath and having along its upper edge a series of holding channels, and a hinge pin retained in said channels; a movable plate extending forwardly from said hinge pin and having an inturned forward edge for contacting the flat forward surface of said exposed sheath along a line just behind said upturned serrated edge, and a series of holding channels cooperating with those of said fixed plate about said pins, said movable plate extending rearwardly of said channels along at least a portion of the length of said plate to provide a handle member serving as a lever means for raising said forward edge from said exposed sheath; and

(4) spring means for continuously urging the forward edge of said movable plate into firm contact With said exposed sheath, said sheath and said fixed plate being mounted on the upright backside of said elongate bar with a plurality of retaining screws.

2. A clamp member suitable for attachment onto the leading fastener-bar support and fitting completely within the channeled space of a lithographic printing press master cylinder and adapted for use in the rapid attachment to and removal from said master cylinder of flexible lithographic printing plate masters, said clamp comprising:

(1) an elongate bar of generally right-triangular crosssectional shape having centrally disposed along the right-angular axis a perforate mounting flange whose base is coplanar with the base surface of said triangular bar, an upright backside, and a forward outer face forming the hypotenuse;

(2) a flexible thin metal sheath conformably attached to atleast the outer face of the elongate bar, the forward edge of said sheath near its juncture with the base surface being longitudinally upturned and said sheath being also segmentally upturned parallel to and closely behind said upturned forward edge;

(3) a two-plate hinge including: a fixed plate having a series of holding channels, and a hinge pin retained in said channels, said fixed plate being attached to said bar whereby the retained hinge pin lies along the juncture of the bar outer face with the upright backside; a movable plate extending forwardly from said hinge pin and having an inturned forward edge for contacting the fiat forward surface of said metal sheath along a line just behind said upturned forward edge, and a series of holding channels cooperating with those of said fixed plate about said hinge pin, said movable plate extending rearwardly of said channels along a central portion of said movable plate to provide a perforate handle member overlying said perforate mounting fiange, said handle member serving as a lever means for raising said forward edge from said exposed sheath; and

(4) spring means for continuously urging the forward edge of the movable plate into firm contact with said exposed sheath.

3. A clamp member comprising:

(1) an elongate bar of generally righttflangular cross-sectional shape having centrally disposed along the right-angular axis a perforate mounting flange whose base is coplanar with the base surface of sm'cl triangular bar, an upright backside, and a grooved forward outer face forming the hypotenuse;

(2) a two-plate hinge including: a fixed plate having a series of holding channels, and a hinge pin retained in said channels; said fixed plate being attached to said elongate bar whereby the retained hinge pin lies along the juncture of the bar forward outer face with the upright backside; a movable plate extending forwardly from said hinge pin and having an inturned forward edge for contacting the grooved portion of the fiat forward outer face of said elongate bar, and a series of holding channels cooperating with those of said fixed plate about said hinge pin, said movable plate extending rearwardly of said channels along a central portion of said movable plate to provide a perforated handle member overlying said perforate mounting flange, said handle member serving as a lever means for raising said forward edge from said grooved outer face; and

(3) spring means for continuously urging the forward edge of the movable plate into firm Contact with said grooved outer face.

4. A clamp member comprising: i

(1) an elongate frame member having a planar base for mounting on a fiat support surface and a broad fiat outer face extending from an edge of said base at an acute angle to and overlying said base, said outer face being perforate to receive a plurality of sheat etaining screws, said base being perforate for fastening to a said support;

(2) hinge pin supporting means along a longitudinal edge of said broad flat outer face remote from said base; i

(3) a hinge pin retained in said hinge pin supporting means;

(4) a flexible thin metal sheath fitting over the broad flat outer face of the elongate bar, said sheath being perforated for passage of said retaining screws and being longitudinally upturned and serrated along the edge of the broad flat outer face adjacent said base, and said sheath being also segmentally upturned parallel to and closely behind said upturned serrated edge, said sheath being attached to said elongate bar with a plurality of retaining screws fitting within corresponding perforations of each;

(5) a movable plate extending forwardly from said hinge pin and having an inturned forward edge for contacting the fiat forward surface of said metal sheath along a line just behind said upturned serrated edge, and a series of holding channels revolvably supported about said hinge pin, said movable plate extending rearwardly of said channels along a central portion of said movable plate to provide a handle member serving as a lever means for raising said forward edge from said metal sheath; and

(6) spring means for continuously urging the forward edge of said movable plate into firm contact with said metal sheath.

5, A clamp member comprising: (1) an elongate frame member having a flat base for mounting on a fiat support surface and a grooved forward flat outer face extending from the forward edge of said base at an acute angle to and overlying said base, said frame member being perforate for application of mounting-screw means for mounting said member on a said support and for mounting on said member a clamp jaw assembly; and (2) a clamp jaw assembly comprising (a) a fixed first hinge plate having along one edge a series of pin-retaining channels, (1)) a hinge pin retained Within said channels, (c) a movable second hinge plate extending forwardly from said hinge pin and having (1.) an inturned forward edge for contacting the depressed surface of said outer face of said frame member defining the bottom of the groove therein, (2) a series of holding channels cooperating with those of said fixed plate about said hinge pin, and (3) a handle member extending rearwardly from said hinge pin and serving as a lever means for raising said forward edge from said grooved outer face, and (d) spring means for continuously urging the forward edge of said movable plate into firm contact with said grooved outer face; said clamp jaw assembly being mounted on said elongate frame member with the hinge pin lying along the upraised rearward edge of said outer face and with the inturned forward edge of said movable plate in alignment with said groove.

References Cited in the file of this patent UNITED STATES PATENTS 2,195,491 M archev Apr. 2, 1940 2,381,461 Moorse Aug. 7, 1945 2,411,881 Janke Dec. 3, 1946 2,453,927 Moorse Nov. 16, 1948 

1. A CLAMP MEMBER SUITABLE FOR ATTACHMENT ONTO THE LEADING FASTENER-BAR SUPPORT AND FITTING COMPLETELY WITHIN THE CHANNELED SPACE OF A LITHOGRAPHIC PRINTING PRESS MASTER CYLINDER AND ADAPTED FOR USE IN THE RAPID ATTACHMENT TO AND REMOVAL FORM SAID MASTERS, SAID CLAMP COMPRISING; (1) AN ELONGATE BAR OF GENERALLY RIGHT-TRIANGULAR CROSSSECTIONAL SHAPE HAVING CENTRALLY DISPOSED ALONG THE RIGHT-ANGULAR ASIX A PERFORATE MOUNTING FLANGE WHOSE BASE IS COPLANAR WITH THE BASE SURFACE OF SAID TRINGULAR BAR, AN UPRIGHT BACKSIDE DRILLED TO TAPPED TO RECEIVE A PLURALITY OF RETANING SCREWS, AND A FORWARD OUTER FACE FORMING THE HYPOTENUSE; (2) A FLEXABLE THIN METAL SHEATH CONFORMING TO THE BACKSIDE AND THE OUTER FACE OF THE ELONGATE BAR, SAID SHEATH BEING PERFORATED FOR PASSAGE OF SAID RETAINING SCREWS, AND BEING LONGITUDINALLY UPTURNED AND SERRATED ALONG THE FORWARD EDGE AND ALSO SEGMENTALLY UPTURNED PARALLEL TO AND CLOSELY BEHING SAID SERRATED EDGE; (3) A TWO-PLATE HINGE HAVING A FIXED PERFORATED FOR PASSAGE OF SAID RETAINING SCREWS WHEN MOUNTED ALONG SAID BACKSIDE AND OVER THE BACK SEGMENT OF SAID SHEATH AND HAVING ALONG ITS UPPER EDGE A SERIES OF HOLDING CHANNELS, AND A HINGE PIN RETAINED IN SAID CHANNELS; A MOVABALE PLATE EXTENDING FORWARDLY FROM SAID HINGE PIN AND HAVING AN INTURNED FORWARD EDGE FOR CONTACTING THE FLAT FORWARD SURFACE OF SAID EXPOSED SHEATH ALONG A LINE JUST BEHING SAID UPTURNED SERRATED EDGE, AND A SERIES OF HOLDING CHANNELS COOPERATING WITH THOSE OF SAID FIXED PLATE ABOUT SAID PINS SAID MOVABLOE PLATE EXTENDING REARWARDLY OF SAID CHANNELS ALONG AT LEAST A PORTION OF THE LENGTH OF SAID PLATE TO PROVIDE A HANDLE MEMBER SERVING AS A LEVER MEANS FOR RAISING SAID FORWARD EDGE FROM SAID EXPOSED SHEATH; AND (4) SPRING MEANS FOR CONTINUOUSLY URGING THE FORWARD EDGE OF SAID MOVABLE PLATE INTO FIRM CONTACT WITH SAID EXPOSED SHEATH, SAID SHEATH AND SAID FIXED PLATE BEING MOUNTED ON THE UPRIGHT BACKSIDE OF SAID ELONGATE BAR WITH PLURALITY OF RETAINING SCREWS. 